I was thinking and came up with this. I know it's wrong but can't find the mistake :((adsbygoogle = window.adsbygoogle || []).push({});

dy/dx sin(x) = cos(x)

dy/dx sin(kx) = kcos(kx)

So dy/dx sin(3x) = 3cos(3x)

Now let Y = 3x

dy/dx sin(Y) = cos(Y) = cos(3x)

3cos(3x) = cos(3x)

3 = 1

Where is the mistake?

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# I Differentiation of sin function where's my mistake?

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